1/12÷(5/6-1/3+2)?
应该是(1/12)÷(5/6-1/3+2)吧?
(1/12)÷(5/6-1/3+2)
=(1/12)÷(5/6-2/6+12/6)
=(1/12)÷[(5-2+12)/6]
=(1/12)÷(15/6)
=(1/12)×(6/15)
=(1/2)×(1/15)
=1/30